Resonant v-type antenna with center loading effected by coil formed integrally with radiating element



E. M KEE 3,251,063

WITH CENTER LOADING EFFECTED LLY WITH RADIATING ELEMENT RESONANT V TYPE ANTENNA BY COIL FORMED INTEGRA Filed Jan. 50, .1964

May 10, 1966 INVENTOR. EDWARD MCKEE WJ ATTORNEY FIG.2

This invention relates to an antenna and more particularly to a transmitting antenna.

The principal object of the invention is the provision of a transmitting antenna having an unusually high gain.

A further object of the invention is the provision of a transmitting antenna in which the physical lengths of the driven elements, director elements and reflector elements are decreased by one-third, while the elements retain their desired electrical length.

A further object of the invention is the provision of a transmitting antenna having a physical shape which cuts down wind resistance and vibration and is so formed that portions of each of the antenna elements act as springs yieldably supporting other portions of said elements.

A still further object of the invention is the provision of a transmitting antenna having'driven, director and reflector elements incorporating coils intermediate their ends and acting to reduce the physical length of the an tenna elements while maintaining their desired electrical length.

The antenna disclosed herein and described as a transmitting antenna may also be used as a receiving antenna. In the embodiment disclosed and described herein, it will be referred to in its capacity as a transmitting antenna polarized vertically and wherein each of the antenna elements includes an integral center load coil so formed that the size of the coil is such that it need not be tuned and its bulk induction is generated by its physical size. The

transmitting antenna formed in accordance with the following disclosure wherein the elements are sized for the 27 me. Citizens band has an actual gain twelve times ments arranged horizontally for horizontal polarization if desired.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute dc partures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

FIGURE 1 is a perspective view of the antenna.

FIGURE 2 is an enlarged detailed elevation on line 22 of FIGURE 1 having parts broken away and parts in cross section.

By referring to the drawings and FIGURE 1 in particular, it will be seen that a transmitting antenna has been illustrated which comprises a principal horizontal support member which is preferably formed of steel or aluminum tubing and which has three pairs of oppositely disposed angularly positioned tubular sockets, 11,

United States Patent 0 It Will be observed that the depending tubular socket 14 is spaced horizontally with respect to the middle pair of the vertically positioned tubular sockets 12, 12 which are themselves spaced horizontally with respect to the tubular sockets 11,11 and 13, 13. In a preferred embodiment of the invention the horizontal support member 10 and the support pole 15 are formed of 1'' OD. tubular stock with the horizontal support member being 10' in length and the vertically positioned pairs of tubular sockets 11, 11 and 12, 12 and 13, 13 being spaced horizontally 5' apart. The vertically positioned tubular sockets 11, 11, 12, 12 and 13, 13 are inclined at a desirable angle from vertical which is approximately 20 in the embodiment described, and which may be varied as desired in keeping with the practice of angling antenna elements to keep the radiation angle low and thereby insure better ground wave coverage.

Still referring to FIGURE 1 of the drawings, it will be seen that in the embodiment disclosed, the center tubular sockets 12, 12 are used to mount a pair of oppositely disposed driven antenna V-elements 16, 16 constituting dipole halves which-are preferably formed of V2" O.D. aluminum tubing. Each of the elements 16, 16 is formed of 8 10" length of aluminum tubing and has a center load coil 17 intermediate its ends, the coil comprising 5 turns each of'which turns is spaced /2" relative to the other and the outer diameter of the coil being 3". The physical length of each of the driven elements is therefore reduced to 6 and the construction results in a relatively compact antenna element having an electrical length-con responding to /2 the wave length of the indicated electrical frequency and formed, as customary in the art, of the two identical elements 16, 16 each of which has an electrical length of A of the indicated wave length.

Still referring to FIGURE lot the drawings, it will be seen that the forward pair of vertical tubular sockets 13, 13 each support a director V-element 18, 18 constituting dipole halves each of which in the disclosed embodiment are formed of a section of /2" aluminum tubing 8' 4" in length prior to the formation of a center load coil 19 therein which reduces its physical length to approximately 6'. The center load coil includes five turns having an outer diameter of 3" and each of the director elements 18, 18 therefore has an electrical length corresponding generally with the driven element 16. The rearmost pair of vertical tubular sockets 11, 11 support reflector V-elementsZtl, 20 constituting dipole halves, each of which has a center load coil 21, 21 and each of which is formed of /2 diameter aluminum tubing 9' 8" in length prior to the formation of the center load coil therein which comprises six turns having an outer diameter of 3 /2" and which coil reduces the physical length of each element 20, 20 to exactly 6.

The three half -wave antenna elements formed of the A wave elements 16, 16, 18, 18 and 20, 20 are individually tuned to a specific frequency band, the director element 18 to a high frequency end, the driven element 16 7O antenna may be held 111 elevated relation to a support member.

to the middle of the frequency band and the reflector element 20 to the low frequency end .to insure'proper bandwidth for better coverage. 1

By referring now to FIGURE 2 of the drawings, an enlarged detail of a portion of the antenna may be seen, and it will be observed that each of the tubular sockets 12, 12 are illustrated as having a longitudinal slot'22 formed inwardly from their outermost ends and a clamp 23 positioned thereabout by means of which the driven antenna elements 16, 16 are secured thereto. Flexible conductors 24 and 25 extend from terminal clamps 26 and 27 on the driven antenna elements 16, 16 respectively to a terminal block 28 which is attached to the horizontal support member 10 and from which terminal block a two 3 conductor lead line 29 extends to the transmitter (not shown).

Still referring to FIGURE 2 of the drawings, -it will be seen that portions of the uppermost driven element 16 are broken away so that the center load coil 17 thereof is illustrated in size proportional to the remainder of the antenna, while sections of the straight portions of the antenna element 16 have been cut away. The outermost ends of the elements 16, 16 are preferably plugged as at 30.

It will occur to those skilled in the art that by changing the physical size and electrical length of the driven, director and reflector elements of the antenna, while maintaining its herring-bone shape, the antenna disclosed herein may be tuned to peak efiiciency on a specific frequency Also, the antenna may be formed so as tobe tuned to any desired frequency by varying the diameter and number of convolutions and over-all length of the center load coils and the physical length of the tubing used in forming the antenna elements.

It will occur to those skilled in the art that the center load coils are integrally formed in the tubing used for the particular element whether it is the driven element, the director element or the reflector element and that the coil diameter and length and spacing of the convolutions change with different frequencies. The center load coils will also increase or decrease in size when the size of the tubing, from which the antenna element is formed, is changed. It will additionally be observed that more than one coil may be used in an antenna element to increase its electrical length.

It will thus be seen that the physical length of the antenna elements in the antenna herein disclosed can be decreased by one-third through the use of the center load coil while maintaining the electrical length of the element as desired. The increased energy radiating from the antenna disclosed herein is believed to be due to the better coupling between the elements due primarily to the center load coils in the antenna elements being in line with each other.

It will further be seen that the antenna is designed to be vertically polarized so that it radiates a vertical shape which is ideally received by vertical whip antennas on various vehicles and the like.

It will thus be seen that a transmitting antenna has been disclosed which meets the several objects of the invention and having thus described my invention, what I claim is:

1. An antenna system including a horizontally disposed 4 support and a pair of herring-bone like conducting Velements planarly arranged midway between the ends of said support, said V-elements being of equal length defining substantially an apex in said support, a connection between said V-elements and a feeder connected thereo, additional pairs of V-elements planarly arranged and spaced along said support, each of the additional pairs of V-elements being of equal length and defining substantially an apex with the apexes of all of said V-elements lying in a substantially straight line corresponding with said support, the two V-elements forming each pair constituting dipole halves, each of said V-elemznts having a center load coil formed integrally therein midway between its ends, each of said center load coils being of a physical size to generate bulk induction in said V-elernent.

2. The antenna system set forth in claim 1 and wherein one pair of said spaced V-elements is of an electrical length enabling it to act as a director and the other one of said pair of spaced V-elements is of an electrical length enabling it to act as a reflector.

3. The antenna set forth in claim 1 and wherein the spacings between successive V-element dipoles dilfer from each other by substantially a common square factor and wherein said V-element dipoles have different electrical lengths with said first pair of V-elements having an electrical length corresponding to the middle of the desired frequency band to which said antenna is tuned.

4. The antenna set forth in claim 1 and wherein the spacings between said successive V-element dipoles differ from each other by substantially a common square factor and wherein adjacent V-element dipoles have different electrical lengths, the spacings between adjacent dipoles being such that a combination of the various dipole lengths and spacings provides a substantially uniform bandwidth response over a desired frequency band.

References Cited by the Examiner UNITED STATES PATENTS 2,419,611 4/1947 Walsh 343749 FOREIGN PATENTS 574,323 5/ 1953 Canada. 886,770 8/ 1953 Germany. 909,583 4/ 1954 Germany. 906,636 9/ 1962 Great Britain.

ELI LIEBERMAN, Acting Primary Examiner.

R. F. HUNT, JR., Assistant Examiner. 

1. AN ANTENNA SYSTEM INCLUDING A HORIZONTALLY DISPOSED SUPPORT AND A PAIR OF HERRING-BONE LIKE CONDUCTING V-ELEMENTS PLANARLY ARRANGED MIDWAY BETWEEN THE ENDS OF SAID SUPPORT, SAID V-ELEMENTS BEING OF EQUAL LENTH DEFINING SUBSTANTIALLY AN APEX IN SAID SUPPORT, A CONNECTION BETWEEN SAID V-ELEMENTS AND A FEEDER CONNECTED THEREOF, ADDITIONAL PAIRS OF V-ELEMENTS PLANARLY ARRANGED AND SPACED ALONG SAID SUPPORT, EACH OF THE ADDITIONAL PAIRS OF V-ELEMENTS BEING OF EQUAL LENGTH AND DEFINING SUBSTANTIALLY AN APEX WITH THE APEXES OF ALL OF SAID V-ELEMENTS LYING IN A SUBSTANTIALLY STRAIGHT LINE CORRESPONDING WITH SAID SUPPORT, THE TWO V-ELEMENTS FORMING EACH PAIR CONSTITUTING DIPOLE HALVES, EACH OF SAID V-ELEMENTS HAVING A CENTER LOAD COIL FORMED INTEGRALLY THEREIN MIDWAY BETWEEN ITS ENDS, EACH OF SAID CENTER LOAD COILS BEING OF A PHYSICAL SIZE TO GENERATE BULK INDUCTION IN SAID V-ELEMENT. 